The invention relates to apparatus for controlling shed formation in a travelling wave loom.
In a known arrangement of this type, a plurality of heddle elements are disposed in parallel, axially spaced relation in at least one heddle holder along a weaving region of the travelling wave loom. Actuating butts at the lower ends of the heddle elements are captured within one of two superposed cam tracks in a succession of cams or guiding members on an adjacent first endless conveyor, such tracks serving to guide the captured heddle element into an upper shed-forming position and a lower shed-forming position, respectively, in accordance with a predetermined program.
At periodic intervals along the succession of guiding members on the first conveyor, adjustment sections are provided for coupling the cam tracks upstream of such adjustment portion in either direct or inverted fashion to the cam tracks downstream of such adjustment portion. Each such adjustment is effective to control the portion of the loom shed during the next portion of the travelling wave cycle.
In such known arrangement, control of the adjustment portion of the succession of guiding members on the first conveyor for the switching of the cam tracks is effected by means of sinkers. Such sinkers are associated with a tiltable element in each adjustment section of the succession of guiding members on the first conveyor, such tiltable section being movable into one of three positions for maintaining the cam track arrangement or for reversing them in one of two opposite senses.
A disadvantage of such facilities is the presence of severe impacts during the movement of the tilting adjustment member, and also during movement of the heddle elements through the tilting member even when no change of cam tracks is to be effected. Such impacts result in rapid wear of the shed-forming portion of the loom, and also constrain such portion to operate at a relatively low speed.